Crops that feed the World 2. Soybean-worldwide production, use, and constraints caused by pathogens and pests

The soybean crop is one of the most important crops worldwide. Soybean seeds are important for both protein meal and vegetable oil. The crop is grown on an estimated 6% of the world's arable land, and since the 1970s, the area in soybean production has the highest percentage increase compared to any other major crop. Recent increases in production coincide with increases in demand for meal and oil. Soybean production was 17 million metric tons (MMT) in 1960 and increased to 230 MMT in 2008. Future soybean production is expected to increase more than other crops, due to expanded production area and higher yields. There are a number of important abiotic and biotic constraints that threaten soybean production by directly reducing seed yields and/or seed quality. Abiotic constraints include extremes in nutrients, temperatures and moisture. These may reduce production directly, but also indirectly through increases in pathogens and pests. Biotic constraints tend to be geographically and environmentally restricted. Some diseases like soybean rust may be explosive by producing copious amounts of air-borne spores. This disease, more so than most, caused great concern when first found invading soybean production areas in Brazil and the United States of America. In contrast, red leaf blotch is a disease restricted to a few countries in Africa, but deserving attention since it has not been intensely studied and adequate management strategies, such as the use of resistant varieties, are not available. Significant losses in soybean yield beyond current levels may have implications for food security because of our dependence on the soybean crop, directly and indirectly for food products. In addition, because the crop is highly nutritious and versatile it offers resources to address world food issues through current and future utilization practices. Future soybean production is expected to increase in proportion to increased demand, and with application of newer genomic technologies, the crop has enormous potential to improve dietary quality for people throughout the world whether consumed as a vegetable crop or processed into various soybean food products.